A Validated Reversed-Phase HPLC Method for the Determination of Atorvastatin Calcium in Tablets

A Reversed-Phase Liquid Chromatographic (RP-LC) assay method was developed for the quantitative determination of atorvastatin calcium in the presence of its degradation products. The assay involved an isocratic elution of atorvastatin calcium in a LiChroCARTR 250*4 mm HPLC Cartridge LiChrospherR 100 RP-18 (5 μm) column using a mobile phase consisting of 0.1% acetic acid solution: acetonitrile (45:55, v/v), pH = 3.8. The flow rate was 0.8 mL/min and the analytes monitored at 246 nm. The assay method was found to be linear from 8.13 to 23.77 μg/mL. All the validation parameters were within the acceptance range. The developed method was successfully applied to estimate the amount of atorvastatin calcium in tablets.Fil: Simionato, Laura Daniela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Ferello, L.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Stamer. S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Repetto, M. F.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Zubata, P. D.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Segall, Adriana Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Expression of the nociceptin precursor and nociceptin receptor is modulated in cancer and septic patients

Background A role of nociceptin and its receptor (NOP) in pain and immune function has been suggested. The hypothesis was that mRNA expression of NOP and the nociceptin precursor pre-pronociceptin (pN/OFQ) in peripheral blood cells differs in end-stage cancer patients suffering from chronic pain and septic intensive care unit (ICU) patients compared with healthy controls. Methods Blood samples were drawn from end-stage cancer patients and septic ICU patients. Additionally, postoperative patients representing individuals with surgical stress and healthy controls were enrolled as comparative groups. NOP and pN/OFQ mRNA expression, quantified by real-time polymerase chain reaction (RT-PCR), was compared between study groups, and associated to opioid medication, pain intensities, and the inflammatory markers procalcitonin (PCT) and interleukin-6. Results NOP expression was significantly higher in cancer patients [normalized ratio, median (inter-quartile range): 10.2 (7.4/17.8)], postoperative patients [8.0 (5.3/10.2)], and ICU patients [6.6 (4.2/9.5)] compared with healthy controls [4.4 (2.7/7.0); P<0.001]. Expression of pN/OFQ was lower in cancer patients [3.8 (1.9/5.9)] and ICU patients [1.9 (1.0/2.7)] but not in postoperative patients compared with healthy controls [7.2 (6.1/9.4); P<0.001]. Increased plasma PCT was associated with decreased pN/OFQ in all patient groups. In cancer patients, no association was seen with pain scores, opioid medication or duration of analgesia, and NOP or pN/OFQ mRNA. Conclusions NOP and pN/OFQ expression in peripheral blood cells was modulated in end-stage cancer and septic patients compared with healthy controls, whereas changes in postoperative patients were minor. The involvement of the NOP-pN/OFQ system in inflammation, impaired immune function, and pain has to be further elucidate

Water quality in the central Nebraska basins, Nebraska, 1992-95

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Central Nebraska Basins Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in waterresource management. Indeed, this report addresses many of the concerns raised by regulators, water-utility managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to the USGS during this NAWQA Study-Unit investigation. Yet, the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live. Land use in central Nebraska appears to affect water quality significantly; streams in rangelands generally had fewer occurrences and smaller concentrations of pesticides than did streams in croplands where corn and soybeans were planted extensively. Subbasins with greater proportions of rangeland, such as the Dismal River, had negligible herbicide concentrations. The largest pesticide concentrations were in storm runoff following pesticide applications. Because some pesticide concentrations may exceed the U.S. Environmental Protection Agency’s (USEPA) drinking-water Maximum Contaminant Levels (MCLs) in storm runoff, the timing and intensity of rainfall has implications for drinking-water supplies. Pesticides in streams from storm runoff may enter alluvial aquifers as a consequence of ground-water withdrawals. Sites with degraded water chemistry commonly had degraded physical habitats as well. Streamflow regulation of the Platte River has affected water quality through habitat alterations that are deleterious to native species. The combination of degraded physical and chemical environments commonly resulted in structurally simple fish communities. CONTENTS National Water-Quality Assessment Program .. 1 Summary of major issues and findings... 2 Environmental setting and hydrologic conditions.... 4 Major issues and findings ... 6 Nitrate content in water is related to agricultural land management 6 Agricultural activities potentially affect the management of public water supplies . 8 Water quality in the Platte River alluvial aquifer may be affected by surface-water quality in areas of ground-water withdrawals .. 10 Aquatic environments potentially are altered by human activities... 12 Aquatic and migratory species are affected directly by changes in the physical characteristics of the Platte River .. 14 Water-quality conditions in anational context ... 16 Study design and data collection .. 20 Summary of compound detections and concentrations ... 22 References . 28 Glossary 3

L-DOPA Is an Endogenous Ligand for OA1

Albinism is a genetic defect characterized by a loss of pigmentation. The neurosensory retina, which is not pigmented, exhibits pathologic changes secondary to the loss of pigmentation in the retina pigment epithelium (RPE). How the loss of pigmentation in the RPE causes developmental defects in the adjacent neurosensory retina has not been determined, but offers a unique opportunity to investigate the interactions between these two important tissues. One of the genes that causes albinism encodes for an orphan GPCR (OA1) expressed only in pigmented cells, including the RPE. We investigated the function and signaling of OA1 in RPE and transfected cell lines. Our results indicate that OA1 is a selective L-DOPA receptor, with no measurable second messenger activity from two closely related compounds, tyrosine and dopamine. Radiolabeled ligand binding confirmed that OA1 exhibited a single, saturable binding site for L-DOPA. Dopamine competed with L-DOPA for the single OA1 binding site, suggesting it could function as an OA1 antagonist. OA1 response to L-DOPA was defined by several common measures of G-protein coupled receptor (GPCR) activation, including influx of intracellular calcium and recruitment of β-arrestin. Further, inhibition of tyrosinase, the enzyme that makes L-DOPA, resulted in decreased PEDF secretion by RPE. Further, stimulation of OA1 in RPE with L-DOPA resulted in increased PEDF secretion. Taken together, our results illustrate an autocrine loop between OA1 and tyrosinase linked through L-DOPA, and this loop includes the secretion of at least one very potent retinal neurotrophic factor. OA1 is a selective L-DOPA receptor whose downstream effects govern spatial patterning of the developing retina. Our results suggest that the retinal consequences of albinism caused by changes in melanin synthetic machinery may be treated by L-DOPA supplementation

Localization of aquaporin CHIP in the human eye: implications in the pathogenesis of glaucoma and other disorders of ocular fluid balance

PURPOSE. The existence of integral membrane proteins that serve as selective water channels has been postulated to explain the movement of water across plasma membranes. Aquaporin CHIP (channel-forming integral membrane protein of 28 kd) is the first such channel to be characterized and is abundant in human erythrocytes and a variety of secretory and absorptive epithelia of the rat. Because disturbances in the movement of water characterize several ocular diseases, the distribution of CHIP in the human eye was studied. METHODS. Affinity-purified antibodies against purified CHIP protein were used for the indirect immunofluorescence localization of CHIP in human eye structures. Labeling was confirmed by immunoblot analyses of membrane preparations from eye structures. RESULTS. CHIP immunolabeling was found in the corneal endothelium, the lens epithelium, the nonpigmented epithelium of the ciliary process, the iris epithelium, and the endothelium of the trabecular meshwork and the canal of Schlemm. CONCLUSIONS. The presence of CHIP water channels in the secretory and absorptive tissues of the human eye provides a mechanism for transcellular water movement and may be important for understanding diseases of the eye that involve excess or insufficient movement of ocular fluid such as glaucoma, cataracts, and Fuch's dystrophy. In addition, the existence of CHIP in the outflow pathways of the human eye provides a novel explanation for the movement of water out of the eye

Glucocorticoids with different chemical structures but similar glucocorticoid receptor potency regulate subsets of common and unique genes in human trabecular meshwork cells

<p>Abstract</p> <p>Background</p> <p>In addition to their well-documented ocular therapeutic effects, glucocorticoids (GCs) can cause sight-threatening side-effects including ocular hypertension presumably via morphological and biochemical changes in trabecular meshwork (TM) cells. In the present study, we directly compared the glucocorticoid receptor (GR) potency for dexamethasone (DEX), fluocinolone acetonide (FA) and triamcinolone acetonide (TA), examined the expression of known GRα and GRβ isoforms, and used gene expression microarrays to compare the effects of DEX, FA, and TA on the complete transcriptome in two primary human TM cell lines.</p> <p>Methods</p> <p>GR binding affinity for DEX, FA, and TA was measured by a cell-free competitive radio-labeled GR binding assay. GR-mediated transcriptional activity was assessed using the GeneBLAzer beta-lactamase reporter gene assay. Levels of GRα and GRβ isoforms were assessed by Western blot. Total RNA was extracted from TM 86 and TM 93 cells treated with 1 μM DEX, FA, or TA for 24 hr and used for microarray gene expression analysis. The microarray experiments were repeated three times. Differentially expressed genes were identified by Rosetta Resolver Gene Expression Analysis System.</p> <p>Results</p> <p>The GR binding affinity (IC₅₀) for DEX, FA, and TA was 5.4, 2.0, and 1.5 nM, respectively. These values are similar to the GR transactivation EC₅₀of 3.0, 0.7, and 1.5 nM for DEX, FA, and TA, respectively. All four GRα translational isoforms (A-D) were expressed in TM 86 and TM 93 total cell lysates, however, the C and D isoforms were more highly expressed relative to A and B. All four GRβ isoforms (A-D) were also detected in TM cells, although GRβ-D isoform expression was lower compared to that of the A, B, or C isoforms. Microarray analysis revealed 1,968 and 1,150 genes commonly regulated by DEX, FA, and TA in TM 86 and TM 93, respectively. These genes included RGC32, OCA2, ANGPTL7, MYOC, FKBP5, SAA1 and ZBTB16. In addition, each GC specifically regulated a unique set of genes in both TM cell lines. Using Ingenuity Pathway Analysis (IPA) software, analysis of the data from TM 86 cells showed that DEX significantly regulated transcripts associated with RNA post-transcriptional modifications, whereas FA and TA modulated genes involved in lipid metabolism and cell morphology, respectively. In TM 93 cells, DEX significantly regulated genes implicated in histone methylation, whereas FA and TA altered genes associated with cell cycle and cell adhesion, respectively.</p> <p>Conclusion</p> <p>Human trabecular meshwork cells in culture express all known GRα and GRβ translational isoforms, and GCs with similar potency but subtly different chemical structure are capable of regulating common and unique gene subsets and presumably biologic responses in these cells. These GC structure-dependent effects appear to be TM cell-lineage dependent.</p

Measurement of the branching ratios of the Z0 into heavy quarks

We measure the hadronic branching ratios of the Z0 boson into heavy quarks: Rb=Gamma(Z0->bb)/Gamma(Z0->hadrons) and Rc=Gamma(Z0->cc/Gamma(Z0->hadrons) using a multi-tag technique. The measurement was performed using about 400,000 hadronic Z0 events recorded in the SLD experiment at SLAC between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct bottom and charm hadron decay vertices with high efficiency and purity, which enables us to measure most efficiencies from data. We obtain, Rb=0.21604 +- 0.00098(stat.) +- 0.00073(syst.) -+ 0.00012(Rc) and, Rc= 0.1744 +- 0.0031(stat.) +- 0.0020(syst.) -+ 0.0006(Rb)Comment: 37 pages, 8 figures, to be submitted to Phys. Rev. D version 2: changed title to ratios, used common D production fractions for Rb and Rc and corrected Zgamma interference. Identical to PRD submissio

Elevated frequencies of leukemic myeloid and plasmacytoid dendritic cells in acute myeloid leukemia with the FLT3 internal tandem duplication

Some 30% of acute myeloid leukemia (AML) patients display an internal tandem duplication (ITD) mutation in the FMS-like tyrosine kinase 3 (FLT3) gene. FLT3-ITDs are known to drive hematopoietic stem cells towards FLT3 ligand independent growth, but the effects on dendritic cell (DC) differentiation during leukemogenesis are not clear. We compared the frequency of cells with immunophenotype of myeloid DC (mDC: Lin−, HLA-DR+, CD11c+, CD86+) and plasmacytoid DC (pDC: Lin−, HLA-DR+, CD123+, CD86+) in diagnostic samples of 47 FLT3-ITD− and 40 FLT3-ITD+ AML patients. The majority of ITD+ AML samples showed high frequencies of mDCs or pDCs, with significantly decreased HLA-DR expression compared with DCs detectable in ITD− AML samples. Interestingly, mDCs and pDCs sorted out from ITD+ AML samples contained the ITD insert revealing their leukemic origin and, upon ex vivo culture with cytokines, they acquired DC morphology. Notably, mDC/pDCs were detectable concurrently with single lineage mDCs and pDCs in all ITD+ AML (n = 11) and ITD− AML (n = 12) samples analyzed for mixed lineage DCs (Lin−, HLA-DR+, CD11c+, CD123+). ITD+ AML mDCs/pDCs could be only partially activated with CD40L and CpG for production of IFN-α, TNF-α, and IL-1α, which may affect the anti-leukemia immune surveillance in the course of disease progression

Direct Measurements of A_b and A_c using Vertex/Kaon Charge Tags at SLD

Exploiting the manipulation of the SLC electron-beam polarization, we present precise direct measurements of the parity violation parameters A_c and A_b in the Z boson - c quark and Z boson - b quark coupling. Quark/antiquark discrimination is accomplished via a unique algorithm that takes advantage of the precise SLD CCD vertex detector, employing the net charge of displaced vertices as well as the charge of kaons that emanate from those vertices. From the 1996-98 sample of 400,000 Z decays, produced with an average beam polarization of 73.4%, we find A_c = 0.673 +/- 0.029 (stat.) +/- 0.023 (syst.) and A_b = 0.919 +/- 0.018 (stat.) +/- 0.017 (syst.).Comment: 11 pages, 2 figures, 2 tables, to be submitted to Physical Review Letters; version 2 reflects changes suggested by the refere